High resolution High Frequency (HF) radar observations of surface currents in the Gulf of Trieste (GoT) are presented and compared to moored subsurface current measurements and to high-resolution simulations from the Northern Adriatic Princeton Ocean Model (NAPOM) oceanographic model. One of transmitters was placed also at the tip of the cape Madonna of Piran. Dominant circulation modes of the GoT, such as the basin-wide cyclonic circulation and the coastal jet outflowing the GoT. The model underestimates of surface currents originate within the low-frequency, diurnal, semidiurnal, and inertial bands. Both radar and model currents do not reproduce the diurnal tidal ellipse structure observed by the moored current meter.
COBISS.SI-ID: 2965071
The coastal northern Adriatic Sea receives pulsed inputs of riverine nutrients, causing phytoplankton blooms and seasonally sustained dissolved organic carbon (DOC) accumulation-hypothesized to cause episodes of massive mucilage. The underlying mechanisms regulating P and C cycles and their coupling are unclear. Extensive set of biogeochemical parameters and community composition were measured in a 64-day mesocosms. We followed the temporal trends of C and P fluxes in P-enriched and unenriched mesocosms. An intense diatom bloom developed then crashed; however, substantial primary production was maintained throughout, supported by tightly coupled P regeneration by bacteria and phytoplankton. Post-bloom DOC accumulation remained elevated despite high bacterial carbon demand. Presumably, a large part of DOC accumulated due to the bacterial processing of primary productivity that adventitiously generated slow-to-degrade DOC. Alpha- and Gamma-proteobacteria dominated the bacterial communities in both mesocosms. However, minor taxa showed dramatic changes in community compositions. Results provide novel insights on post-bloom C and P dynamics and mechanisms.
COBISS.SI-ID: 2983247
We assessed the impact of anoxia on the mortality rates of selected meiofauna groups (copepods, nematodes) during hypoxia and anoxia. This involved comparing two techniques to enumerate meiofauna: labeling with CellTracker Green (CTG), a vital fluorogenic probe developed to stain only living cells/animals, and staining with the more traditional, non-vital biological stain Rose Bengal (RB). The latter significantly overestimated the number of living copepods because it also marked freshly dead but not yet decomposed individuals. The CTG approach better resolved the initial, fine-scaled processes. This approach will have great implications on the correct evaluation of the impact of anoxia on benthic animals.
COBISS.SI-ID: 2809423
In the present study we tested the influence of sample size on reference condition values and within sample ecological quality ratio variability of six commonly used ecological indices, in order to optimise monitoring for the assessment of ecological quality status of water bodies using benthic invertebrates. Based on the results, the use of at least three replicates is suggested to obtain reliable measures of reference condition and EQR for the assessment of ecological status in the Gulf of Trieste
COBISS.SI-ID: 2605903
Ancient mariners knew that dust whipped up from deserts by strong winds travelled long distances, including over oceans. Attached microorganisms travel along the dust particles from the source and are deposited somewhere else. Satellite remote sensing revealed major dust sources the Bodélé Depression in the Republic of Chad. From this region microorganisms start the journey, travel mostly over the Mediterranean sea and are deposited over Alps. We analysed desert sand from various locations in Chad and dust that had blown to the Cape Verde Islands. High throughput sequencing techniques combined with classical microbiological methods showed that the samples contained a large variety of microbes well adapted to the harsh desert conditions and are therefore capable of surviving harsh atmospheric environment. Most predominant taxa are widely distributed land inhabitants that are common in soil and on the surfaces of plants. These findings support that some bacteria can be distributed globally and some are local inhabitants. Since only few pathogenic strains were found therefore the African dust is not a large threat to public health.
COBISS.SI-ID: 30514393